The present invention relates in general to a gas cooled electrical junction assembly, and more particularly, to a gas cooled electrical junction assembly located between a parallel ring and main lead used in a turbine generator within a power generation plant.
Many power generation plants produce electricity by converting energy (e.g. fossil fuel, nuclear fission, hydraulic head, geothermal heat) into mechanical energy (e.g. rotation of a turbine shaft), and then converting the mechanical energy into electrical energy (e.g. by the principles of electromagnetic induction). Fossil fuel power generation plants typically use a turbine to convert the fossil fuels into mechanical energy and a generator to convert the mechanical energy into electricity.
One aspect of the above-described power generation scheme involves a junction assembly that is located between the generator""s parallel rings and the generator""s main lead. The junction assembly conducts AC electrical current from the parallel rings to the main lead. The junction assembly must also accept and attenuate the vibration that the parallel rings and coil windings place upon it, as well as withstand the high temperature caused by the electrical current that runs through it.
As shown in FIG. 1, to meet these requirements, a conventional junction assembly 10 typically comprises several flexible connectors 12 (sometimes set back-to-back) secured to a thin, flat elongated junction 14. The flexible, connectors 12 are constructed of conductive wire strands 16 to provide an electrically conductive path and to provide the junction assembly 10 with flexibility to accept the various and varying forces and loads applied by the parallel rings 20, main lead 22 and other generator components. The junction 14 secures the flexible connectors 12 relative to the parallel rings 20 and main lead 22, and has a passageway 18 through which a coolant flows to cool the flexible connectors 12 by conduction.
There are several shortcomings, however, to the above-described conventional junction assembly. One shortcoming involves the tracked coolant route, which causes any and all cooling of the flexible connectors to be performed by conduction along and from the passageway. Another shortcoming of the tracked coolant route involves the undesirable overcooling of flexible connectors located near the coolant inlet and undercooling of flexible connectors located near the coolant outlet.
There is thus a need for a junction assembly that more efficiently cools the flexible connectors. There is also a need for a junction assembly that more uniformly cools the flexible connectors.
One aspect of the present invention thus involves a junction assembly comprising a first electrically conductive junction having at least one inlet; a second electrically conductive junction having at least one outlet; a plurality of electrically conductive flexible connectors disposed between and attached to the first and second junctions; and a casing surrounding the inlet and the outlet, whereby coolant can flow in from the inlet, throughout the casing interior, and out through the outlet.
Another aspect of the invention involves method of cooling an electrically conductive element comprising providing at least one electronically conductive element disposed between and attached to a second and a third electrically conductive element, the second and third elements each having at least one opening; providing a casing that surrounds the openings in the second and third elements; and flowing coolant through the opening in the second element and through the opening in the third element such that the coolant cools the first element.